After you have selected a database or search engine, it's time to think about constructing your search. If you are researching a specific topic, the first step is to identify the main concepts of your topic.

For example, if you are researching about the use of bacteria as a biological weapon, you need to identify the main concepts of your search:

When searching for scientific literature, It is important to consider alternative words and phrases, because not all authors use the same words when writing about a topic. Consider the following:

• Synonyms and other related terms.
• Scientific names in your search.
• Alternative spellings, abbreviations, or acronyms.

After consulting an encyclopedia and recent news articles you learn that anthrax is one of the most common bacteria used as a weapon and that the scientific name for anthrax is Bacillus anthracis. You also notice that biological weapons is sometimes referred to as bioterrorism.